Cutting catheters, commonly known as papillotomes, are utilized for a variety of surgical procedures for cutting tissue and, more particularly, severing papilla at a number of different anatomical sites. One particular surgical procedure involves positioning an endoscope through the esophagus, stomach, and duodenum of a patient and positioning the tip thereof at the papilla of Vater. The common duct secretes liver bile into the duodenum and digestive tract at the papilla of Vater. Secretions and mineral deposits form calculi in the common duct and can cause an interruption of liver bile flow into the duodenum. In addition, the calculi can irritate the tissue surrounding the papilla of Vater and cause further blockage of liver bile. A papillotome is typically inserted through the endoscope into the papilla of Vater to enlarge the duct opening. This permits calculi to pass therethrough into the duodenum and clear the duct opening for resumed liver bile flow.
The papillotome utilized for this procedure is commonly 200 cm long with an electrically conductive cutting wire extending through a multi-lumen 6 French catheter. One lumen of the catheter is utilized for passing the electrically conductive cutting wire therethrough. Another lumen of the catheter is typically utilized for extending a wire guide therethrough and positioning the papillotome at the proper anatomical site through the endoscope. The proximal end of the papillotome typically includes a manually operated handle attached to the cutting wire so as to deflect the distal end of the catheter. This is done to form a loop at the distal end of the cutting catheter to engage tissue and, more particularly, papilla. In addition, the deflection of the catheter tip is used to position the cutting wire, such as in the papilla of Vater for enlarging the opening thereat.
One problem associated with this particular papillotome construction is the proximal connection of the multi-lumen catheter to the handle. As the handle is operated, the cutting wire causes compression of the multi-lumen catheter and concentrates the stress at the connection of the multi-lumen catheter and the handle. As a result, longitudinal compression of the multi-lumen catheter at the handle connection causes radial expansion of the plastic material beyond its elastic limit. Further compression of the multi-lumen catheter results in twisting and inelastic deformation of the catheter tube. A further consequence of this inelastic deformation is rupturing and tearing of the multi-lumen catheter wall near the connection of the catheter to the handle. This presents an electrical hazard to the patient as well as the attending physician.
Attempts to correct this inelastic deformation problem have included reinforcing the connection of the catheter to the handle with, for example, an outer reinforcing tube tightly positioned around the proximal end of the catheter tube and the distal end of the handle. Unfortunately, this has merely transferred the concentration of stress distally away from the catheter and handle connection. As a result, the multi-lumen catheter again inelastically deforms, ruptures and tears just distal of the reinforcement. Reinforcement of the entire catheter length is usually not possible since the endoscope limits the diameter of the multi-lumen catheter. The selection of stiffer materials has also been unsatisfactory due to the fact that the papillotome is extremely long and needs to be flexible for its tortuous journey.